/*
 * TermInfo#tigetnum(capname) => int
 *
 * TermInfo#tigetnum returns a numeric capability specified by capname.
 */
static VALUE
rt_tigetnum(VALUE self, VALUE v_capname)
{
  int ret;
  setup(self);
  ret = tigetnum(StringValueCStr(v_capname));
  if (ret == -2) { rb_raise(eTermInfoError, "not a numeric capability"); }
  if (ret == -1) { rb_raise(eTermInfoError, "canceled or absent numeric capability"); }
  return INT2NUM(ret);
}